Organic foods hold the same nutritional value as ordinary foods, according to research from the London School of Hygiene & Tropical Medicine.

The British study, published Thursday in the American Journal of Clinical Nutrition, looked at 50 years of research, comparing nutrient levels in organic and non-organic foods.

"A small number of differences in nutrient content were found to exist between organically and conventionally produced foodstuffs, but these are unlikely to be of any public health relevance," author of the report Alan Dangour told Reuters.

Researchers said there is no significant amount of nutritional value in eating organic and consumers pay higher prices for the food's perceived health benefits.

"Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority," Dangour added.

However, organic food advocates say the study did not consider the ill-effects from pesticide residue and other chemicals.

Steffan Browning of the New Zealand Soil and Health Association, which represents organic farmers, called the study "very selective."

"It found several nutrients were higher in organic food but downplayed that," he said.

The British Soil Association created a counter-list of nutritional differences between organic and traditionally processed food.

Some listed facts are that organic food has on average 12 percent more protein, 11 percent more zinc, and 53 percent more beta carotenes than conventional food.

The London School of Hygiene & Tropical Medicine estimates the global organic food business to be worth over $45 billion.